Originally Posted by ChrisSlicks

Highly oxygenated fuels can be moderately corrosive. As long as you're not using it 100% of the time you should be fine.

I would mix it 50/50 - but don't expect a huge power bump. The car feels slightly more responsive and seems to fade less towards the end of the session when heat soak usually causes the ECU to start to pull some advance.

Most of the time I just stick to 93, race gas isn't worth the money unless they're selling it cheap.